We Can’t Rely on Drought-Busting Atmospheric Rivers Anymore

Atmospheric rivers are nothing short of a miracle for California. But climate change is altering their character. 

December 16, 2021

Rather than telling the seasons by temperature fluctuations, Bay Area locals can tell the seasons by the hue of the hills. Are the hills brown? Green? A mixture of the two? This past summer they appeared to be darker brown than the previous summers we’ve had—the light blonde color of the grasses gradually yielding to orange-brown, and dark brown as we’ve gone deeper and deeper into this dry season—the landscape almost mirroring the colors of fire season, flashing orange and black in mourning and solidarity with the thousands of acres burning across the region.

One of my favorite things about the Northern California rainy season is to notice how green the hills get after only a couple storms. Seeing the arid hills turn into lushness in a matter of weeks. Seeing before-and-after imagery illustrating that the Sierra’s snowpack was re-charged.

While we can see sprinkles here and there from smaller storms, the source of major winter storms is almost always atmospheric rivers. These drought-busters are incredible, especially for the drought-prone state of California and its Pacific Northwest neighbors. Instead of relying on consistent precipitation throughout the rainy season, we can sometimes get by on a handful of storms. Atmospheric rivers are essentially a fertile delta, falling out of the sky. Atmospheric rivers are nothing short of a miracle.

But the local impacts of global warming are making us continuously grapple with either drought, deluge or both at the same time. Can we rely on these miracle-working storms anymore? Are the miracles of atmospheric rivers turning into a menace? The rainy season is becoming shorter and starting later, elevating the importance of atmospheric rivers as fire-season stoppers. And while California can breathe a little easier when it comes to fire risk and smoke-polluted skies in the rainy season, we currently still face the threat of multi-year drought.

Which means atmospheric rivers, and all that they bring, are more crucial than ever – and they’re changing, too. It’s not just future climate model simulations, but a new reality unfolding before our eyes.

It’s not only about the timing or frequency of atmospheric rivers—the very character of atmospheric river storms is warming and therefore transitioning to smaller and smaller percentages of snow versus rain, even if the same amount of water falls from the sky. This has implications for a leaner Sierra snowpack and a greater risk of drought.

We can wait around for miracle seasons of numerous adequately snowy atmospheric rivers to save us from drought, or we can change how we relate to atmospheric rivers and the lack of them.

Atmospheric rivers will continue to arrive, but research is showing that they will continue to warm and intensify. As a result, their benefits will be more difficult to harness and more difficult to forecast. And when it comes to the snowpack as a reservoir in the Western United States, there will simply be less snow. Put simply, the days of “reliable” miracles as a drought solution are over.

Crucially, though, this is not the end of the story. We can wait around for miracle seasons of numerous adequately snowy atmospheric rivers to save us from drought, or we can change how we relate to atmospheric rivers and the lack of them. We can and must change how we relate to water, whether that’s the water in our faucets, in the Bay, or in the rivers in the sky. We must adapt.

The process of adaptation will affect everything, from water utilities to higher education to agriculture to power distribution systems — in both the electrical sense and the political sense. It will mean transforming how we relate to one another, from the interpersonal to the institutional.

As a graduate student researching atmospheric rivers and how they were changing, I thought it would be effective to publish my work in scientific journals, and then wait for leaders and decision-makers to respond appropriately. Water agencies would adopt the information and change their policies; water consumers would learn the science and change their behavior to reflect reality. Instead, I realized I was relying on a miraculous uptake of scientific knowledge by decision-makers, as if knowledge by itself contained the power to do things differently. Last year’s orange skies shook me into re-thinking my scientific career and the usefulness of the end products of my research. If we are going to adapt to increasing droughts and floods, the challenge before us is to help build connections between scientists and water managers, between water managers and the communities they serve, and between scientists and communities. In this moment where the national political conversation focuses on infrastructure, I realized we needed bridges and pathways of the relational variety, not just the asphalt variety.

I’m now working with water utilities to adapt to the changes they’re seeing on the ground. I analyze the flow of knowledge across organizational silos rather than the flow of water. This work is requiring time to relate, time to listen, and time to understand the organization, all practices that are counter-cultural in our fast-paced, individualist Western culture. Most challenging of all, it is requiring me to de-center myself and my academic knowledge and instead elevate other forms of knowledge, including experiential knowledge.

While I work on communication as a critical part of adaptation, other colleagues work to connect groups already doing the work, build networks, push for more equitable academic labor conditions, and hold difficult and courageous climate conversations in the communities they are already embedded in. Regardless of the avenue, one unifying hallmark of adaptation is not waiting for miracles—whether from the sky or from powerful decisionmakers—and taking action in community.

So while the sound of rain lulls us into a tempting forgetfulness about our current exceptional drought, we must remain alert. And beyond staying alert, we have choices to make. We can preserve what’s left of atmospheric rivers’ miracle-working power or let it, quite literally, melt away. We can invest and build resilience in our water infrastructure, or be swept away by the few, but severe, storms that we receive. We can make a just transition to a fossil-free society, or resign ourselves to the false hope, year after year, that Maybe this winter, it will snow; maybe next year, the reservoirs will be full … We must take action that reflects the current reality of our changed and changing climate.

About the Author

Katerina R. Gonzales is a climate scientist who bridges the gap between climate research and practice. Born and raised in Colorado, she grew up deeply acquainted with the increasing presence of drought, flood, and wildfire. She recently finished her dissertation at Stanford University on West Coast atmospheric rivers, and is now a postdoctoral fellow at the University of Minnesota.